//创建和初始化地图函数：
function initMap() {
    createMap();//创建地图
    setMapEvent();//设置地图事件
    addMapControl();//向地图添加控件
    addMapOverlay();//向地图添加覆盖物
}

function createMap() {
    map = new BMap.Map("map");
    map.centerAndZoom(new BMap.Point(120.778659, 31.294661), 16);
}

function setMapEvent() {
    map.enableScrollWheelZoom();
    map.enableKeyboard();
    map.enableDragging();
    map.enableDoubleClickZoom()
}

function addClickHandler(target, window) {
    target.addEventListener("click", function () {
        target.openInfoWindow(window);
    });
}

function addMapOverlay() {
    var markers = [
        {
            content: "公司地址",
            title: "中科纳迪",
            imageOffset: {width: 0, height: 3},
            position: {lng: 120.778659, lat: 31.294661}
        }
    ];
    for (var index = 0; index < markers.length; index++) {
        var point = new BMap.Point(markers[index].position.lng, markers[index].position.lat);

        var marker = new BMap.Marker(point, {
            icon: new BMap.Icon("http://api.map.baidu.com/lbsapi/createmap/images/icon.png", new BMap.Size(20, 25), {
                imageOffset: new BMap.Size(markers[index].imageOffset.width, markers[index].imageOffset.height)
            })
        });
        var label = new BMap.Label(markers[index].title, {offset: new BMap.Size(25, 5)});
        var opts = {
            width: 200,
            title: markers[index].title,
            enableMessage: false
        };
        var infoWindow = new BMap.InfoWindow(markers[index].content, opts);
        marker.setLabel(label);
        addClickHandler(marker, infoWindow);
        map.addOverlay(marker);
    }
    ;
}

//向地图添加控件
function addMapControl() {
    var scaleControl = new BMap.ScaleControl({anchor: BMAP_ANCHOR_BOTTOM_LEFT});
    scaleControl.setUnit(BMAP_UNIT_IMPERIAL);
    map.addControl(scaleControl);
    var navControl = new BMap.NavigationControl({anchor: BMAP_ANCHOR_TOP_LEFT, type: BMAP_NAVIGATION_CONTROL_LARGE});
    map.addControl(navControl);
}

var map;
initMap();